A
Web service is a method of communication between two electronic devices over the Web The
W3C defines a "Web service" as "a software system designed to support
interoperable machine-to-machine interaction over a
network". It has an interface described in a machine-processable format (specifically Web Services Description Language, known by the acronym
WSDL). Other systems interact with the Web service in a manner prescribed by its description using
SOAP messages, typically conveyed using
HTTP with an
XML serialization in conjunction with other Web-related standards.
The W3C also states, "We can identify two major classes of Web services,
REST-compliant Web services, in which the primary purpose of the service is to manipulate XML representations of Web resources using a uniform set of "
stateless" operations; and arbitrary Web services, in which the service may expose an arbitrary set of operations."
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